CN112074444B

CN112074444B - Driver assistance system and method for autopilot with automatic longitudinal guidance

Info

Publication number: CN112074444B
Application number: CN201980030370.0A
Authority: CN
Inventors: F·科希胡贝
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 2018-05-09
Filing date: 2019-05-03
Publication date: 2023-11-03
Anticipated expiration: 2039-05-03
Also published as: WO2019215051A1; US20210188323A1; DE102018207301A1; CN112074444A; US11685410B2

Abstract

The invention relates to a driver assistance system (FAS) for a motor vehicle (F) for automatic driving with automatic longitudinal guidance, wherein the automatic longitudinal guidance is started while taking into account a predefinable target speed when the automatic longitudinal guidance is active in an automatic mode. The system comprises: -a first recognition unit (E1), the first recognition unit (E1) being configured for recognizing a defined standstill condition occurring as a result of a preceding automatic braking to standstill process of the motor vehicle (F); -a second recognition unit (E2), the second recognition unit (E2) being configured for recognizing an accelerator pedal operation (gp); and an evaluation and control unit (SE) configured for activating a manual mode (aMM) when an accelerator pedal operation is identified during the identified defined standstill situation.

Description

Driver assistance system and method for autopilot with automatic longitudinal guidance

Technical Field

The invention relates to a driver assistance system for a motor vehicle and a method for a motor vehicle for automatic driving with automatic longitudinal guidance, wherein longitudinal control is initiated by taking into account a predefinable target speed when automatic longitudinal guidance is active in an automatic mode.

Background

Motor vehicles with automatic longitudinal guidance (so-called speed control systems) have long been known. Most currently available speed control systems regulate the speed of a motor vehicle to a desired or target speed preset by the driver. In addition to these longitudinal control systems, longitudinal control systems that are extended with distance control, so-called distance-dependent longitudinal control systems or speed control systems, are also available from some manufacturers. For example, the applicant of the present patent application provides such a system, under the name "active cruise control (Active Cruise Control)", which enables automatic guidance of a motor vehicle at a desired or correspondingly lower speed while maintaining a desired distance from the preceding vehicle. The principle is here the well known longitudinal control or cruise control which maintains a specific preset speed and is extended with an additional distance function or following driving mode, so that such "active" cruise control is also possible in dense highway traffic and rural road traffic. Such so-called "active cruise control" will maintain a preset desired or target speed (=free running mode) when its own lane is idle. The distance sensor system mounted on the motor vehicle can in particular operate on the basis of radar and/or cameras and/or lasers, if it recognizes a target object or (motor) vehicle travelling ahead on its own lane, adapting its own speed to the speed of the preceding motor vehicle, for example by triggering an appropriate braking torque or driving torque, so that the distance control contained in the "active cruise control" or the corresponding longitudinal control system automatically maintains a target distance suitable for this situation, or more precisely maintains a preset time interval (=following driving mode) with the preceding motor vehicle or target object.

Recent developments in driver assistance systems with automatic longitudinal guidance, optionally by taking into account a maximum speed or a maximum target speed preset by the driver, enable automatic speed adjustment according to the criteria of road traffic regulations (StVO) and driving safety. Therefore, the vehicle generally travels at a maximum allowable speed or a recommended speed (target speed) prescribed by the corresponding road, and maintains a distance suitable for the external environment from the vehicle ahead, or brakes accordingly for cornering and steering processes. Such improved development can also be used in the category of automatic driving modes.

Disclosure of Invention

The object of the present invention is to provide a system which is improved with respect to the comfort of the vehicle occupants and a corresponding method for a driver assistance system with automatic longitudinal guidance.

This object is achieved by a driver assistance system, a method and a correspondingly designed computer program product according to the invention. Advantageous embodiments are given below.

The invention is based on a substantially known driver assistance system (speed control system) for a motor vehicle for automatic driving with automatic longitudinal guidance, wherein the longitudinal control is carried out in an automatic mode designed as the free-running mode described above or in an automatic mode designed as the following-running mode, depending on the traffic environment, when automatic longitudinal guidance is active. If the automatic braking process is carried out until it is stationary, in the known system, the automatic continuation of the travel is only allowed after user confirmation, at least in a longer stationary phase, so that acceleration and automatic longitudinal guidance are carried out. After the confirmation, the automatic longitudinal direction in the free running mode or the automatic longitudinal direction in the following running mode is resumed according to the traffic condition. The confirmation may be performed by operating a control element (e.g., a resume key) or by lightly depressing the accelerator pedal.

The invention is based on the following recognition: in some cases (for example, before an intersection or a cornering situation), braking of the vehicle until stationary is performed in the category of automatic longitudinal guidance, which is not in each case desirable in the restoration of travel according to the known follow-up and free-running modes. In particular, in some traffic situations, in which there is no preceding vehicle when automatic longitudinal guidance is resumed from a standstill of the vehicle, acceleration to the set target speed or maximum allowable speed does not always correspond to the driver's expectations.

In view of the above, the core of the invention is to identify a situation in which, after the vehicle has been braked automatically to a standstill, it is not desirable to perform automatic longitudinal guidance in an automatic mode (free-running mode or following-running mode) and to react accordingly without strongly affecting the comfort of the automatic longitudinal guidance of the vehicle. If this is identified, the conventional logic of automatic longitudinal booting should be at least temporarily disengaged without significantly changing the overall logic.

Against this background, according to a first aspect of the invention, a driver assistance system for a motor vehicle is proposed for automatic driving with automatic longitudinal guidance, wherein the automatic longitudinal guidance is usually initiated taking into account a predefinable target speed when the automatic longitudinal guidance is active in an automatic mode (=following drive mode or free drive mode). The driver assistance system includes:

a first recognition unit configured to recognize a defined standstill condition which occurs or has occurred as a result of a preceding automatic braking to standstill process of the motor vehicle,

-a second recognition unit configured to recognize an accelerator pedal operation, and

-an evaluation and control unit configured for at least temporarily activating the manual mode when an accelerator pedal operation is identified in or during the identified defined stationary situation.

Similarly, according to another aspect of the invention, a method for automatic driving with automatic longitudinal guidance is proposed, wherein when automatic longitudinal guidance is active in an automatic mode (=following or free running mode), automatic longitudinal guidance is initiated taking into account a predefinable target speed, and the method comprises the following steps:

identifying a defined standstill condition which arises as a result of a preceding automatic braking to standstill process of the motor vehicle,

-identifying an accelerator pedal operation, and

-activating the manual mode at least temporarily when an accelerator pedal operation is identified in or during the identified defined stationary situation.

The improvements presented below apply both to the system according to the invention and to the method according to the invention, in particular also to a computer program product with control instructions which, when executed on a computer, perform the proposed method.

In the context of this document, the term "autopilot" is understood to mean a drive with automatic longitudinal guidance or an autonomous drive with automatic longitudinal and transverse guidance. The term "autopilot" includes autopilot with any degree of automation. Exemplary degrees of automation are assisted driving, partially automated driving, highly automated driving or fully automated driving. These degrees of automation are defined by the federal highway institute (BASt) (see BASt publication "Forschung kompakt", version 11/2012). In assisted driving, the driver continues to perform longitudinal or transverse guidance, while the system takes over the respective other functions within certain limits.

The motor vehicle may be any type of vehicle with a drive system designed to participate in road traffic and to allow automatic intervention in longitudinal guidance. The drive system may be, for example, a conventional drive system with an internal combustion engine, a hybrid drive system with an internal combustion engine and an electric motor, or a purely electric drive system. Other drive systems are also contemplated.

The target speed may be preset manually by the driver or may be preset automatically. In the case of an automatic preset or an automatically influenceable preset, the target speed may be preset according to a maximum allowable speed or a recommended speed (target speed) preset for the corresponding road.

The first recognition unit is configured to recognize a defined standstill situation which has occurred as a result of a preceding automatic braking to standstill process of the motor vehicle, for which purpose it can evaluate the relevant sensor signals (e.g. speed sensor signals, camera signals, etc.) or detected and/or processed signals which access other systems or units. The second recognition unit configured to recognize operation of the accelerator pedal may likewise evaluate the associated sensor signal (e.g., accelerator pedal sensor) or the detected and/or processed signal accessing other systems or units. The first recognition unit and the second recognition unit may be designed as separate units, may be combined as one unit, or may be part of an evaluation and control unit.

The evaluation and control unit is configured for activating a manual mode when an accelerator pedal operation is identified in or during the identified defined stationary situation. The evaluation and control unit can send the respective actuation signal directly to the actuator (drive, brake) influencing the longitudinal guidance, or to a unit connected between them, which initiates the respective intervention in the longitudinal guidance on the basis of this requirement and optionally further requirements for the longitudinal acceleration.

Advantageously, the defined standstill situation, which arises as a result of the automatic braking to standstill process before the motor vehicle, can only be reached if the motor vehicle has not braked to standstill because of the object travelling in front. In a particularly advantageous embodiment of the invention, a defined standstill situation is detected if the motor vehicle automatically brakes to standstill as a result of the detected (associated) traffic infrastructure event. Related traffic infrastructure events (traffic signs, traffic lights, traffic rules such as "right-hand first") should be understood as such events that are important for motor vehicles. For example, if different traffic infrastructure events are applicable to different driving maneuvers (turning or straight at an intersection) that are imminent, it may be advantageous to first explicitly identify the traffic infrastructure event that is relevant to the driving maneuver so that only the traffic infrastructure event is considered.

In a further advantageous embodiment of the invention, the defined standstill situation is identified in particular if the motor vehicle automatically brakes to standstill due to an identified (associated) traffic infrastructure event (e.g. giving a preemption flag, right-hand priority rule) requiring that the other road user be given a preemption and/or a traffic infrastructure event (parking flag, red traffic light) temporarily prohibiting continued traffic. If such a traffic infrastructure event is identified, it may be assumed that the driver does not necessarily want to remain in an automatic mode while driving back from rest, as there is still a need to increase the attention of other road users.

Since an increased attention is required in particular when the vehicle is restarted without the road user being in front of the motor vehicle so that the speed of the vehicle itself is not limited, in a further advantageous embodiment of the invention, the manual mode is only activated when an accelerator pedal operation is recognized in or during the recognized defined standstill situation, if no vehicle or object in front is recognized at the point in time of the accelerator pedal operation, which in any case temporarily limits the acceleration of the vehicle to the maximum permissible speed or target speed.

The main difference between the above-mentioned manual mode, which is defined as initially being activated, and the automatic mode of automatic longitudinal guidance is that the speed or acceleration of the vehicle to be set is not set on the basis of a preset target speed but by taking into account the driver's (other) driver presets. Advantageously, in the activated manual mode, a driving speed dependent on the accelerator pedal operation is activated, which is in particular at most a speed preset by the accelerator pedal operation to be activated. In order to give the driver at least a sense of controlling the driving speed or acceleration by himself in this case, the driving speed or acceleration is ideally derived directly from the operation of the accelerator pedal, so that the driving speed or acceleration which would occur if the automatic longitudinal guidance were deactivated is also present.

Unlike the automatic mode, manual deceleration is also preferably allowed in the manual mode without interrupting or disabling the automatic longitudinal guidance. In a further advantageous embodiment, the device according to the invention additionally comprises a third recognition unit, which can be part of the first and/or second recognition unit and which is configured to recognize a brake pedal actuation, in order to be able to achieve a deceleration of the vehicle in manual mode without interrupting or disabling the automatic longitudinal guidance. If an operation of the brake pedal is recognized in the active manual mode, braking of the vehicle is initiated without exiting the manual mode. In contrast to the basic logic of the automatic mode, in which an interruption or deactivation of the automatic longitudinal guide is triggered when the brake pedal is operated under active longitudinal guide, an interruption or deactivation of the automatic longitudinal guide is not triggered in this case. When a brake pedal operation is identified in the active manual mode, braking of the vehicle is advantageously triggered without exiting the manual mode only if the brake pedal operation or a brake value associated with the brake pedal operation (e.g., a requested or triggered deceleration, a requested or triggered brake torque, a requested or established brake pressure) does not exceed a preset brake threshold. If the braking threshold is exceeded, automatic longitudinal guidance will be interrupted or disabled.

In a further advantageous embodiment of the invention, a suitable processing method is proposed, so that an automatic mode can be simply and reasonably exited from the manual mode and entered. Advantageously, it can be provided that the active manual mode is automatically deactivated if at least one predefined interrupt rule is fulfilled. With the manual mode deactivated, reactivation of the automatic mode takes place simultaneously, so that an automatic longitudinal guidance takes place taking into account a preset target speed in the free-running mode or the following-running mode.

The activated manual mode (and the automatic mode) is advantageously deactivated if the following conditions are fulfilled in the sense of an interruption rule:

-the driving speed exceeds a preset speed limit, and/or

The distance travelled in manual mode and/or the distance travelled since the passage of the identified (related) traffic infrastructure event exceeds a preset distance limit value, and/or

Identifying an operation on the defined control element,

-the identified steering situation reaches or exceeds a preset steering angle, and/or

-leaving a predetermined traffic zone for traveling in manual mode.

The speed limit may be a speed limit that may be fixedly or variably preset. The value may be preset and/or set and/or adjusted based on the acquired data (e.g. in urban area, outside urban area, according to road class, weather, time, traffic environment) and/or according to driver requirements and/or according to driving style or driving behavior, for example.

Similarly to the speed limit value, the distance limit value may also be fixedly or variably preset. The limit value can be preset and/or set and/or adjusted, for example, on the basis of the acquired data (for example, in urban areas, outside urban areas, on the basis of road class, weather, time, traffic environment) and/or on the basis of driver requirements and/or on the basis of driving style or driving behavior.

The operation of the defined control element can be understood, for example, as the operation of an existing Resume button, which normally causes automatic longitudinal guidance to Resume from an interrupted state. The operation of a so-called SET button, which normally triggers the activation of an automatic longitudinal guidance from an interrupt state, can also be evaluated and correspondingly considered.

In the case of an identified steering situation (e.g., right turn), the evaluation of the preset steering angle being reached or exceeded enables a (at least almost) closed traffic situation to be identified in a simple manner, in which manual longitudinal guidance of the vehicle is necessary and advantageous. The steering angle may be fixedly or variably preset in particular based on existing navigation data (in combination with route data). Thus, for example, a vehicle turn of more than 90 ° (about 96 °) is set according to the navigation data at the time of right turn.

The following traffic area may be, for example, an intersection area, from which the manual mode should be automatically deactivated when exiting. If the driver "fumbly" into (eintent) an intersection area and then leaves the intersection area, it can be assumed that the driver wishes to return to the automatic mode of automatic longitudinal guidance.

Additionally, these interrupt rules may be associated with other conditions. For example, the manual mode may be deactivated and returned to the automatic mode only when the operation of the accelerator pedal is withdrawn after a speed limit and/or a distance limit has been exceeded and/or after leaving a defined traffic zone. Here, a proper transition from the "manual" driving speed to the speed preset in the automatic mode must be made.

Drawings

The invention will now be explained in more detail by means of the following examples. Wherein:

figure 1 shows traffic conditions relevant to the present invention,

fig. 2 shows an exemplary structure of a driver assistance system according to the present invention, and

fig. 3 shows a simplified flow chart of the method according to the invention.

Detailed Description

The traffic situation shown in fig. 1 shows a so-called t-junction, in which a vehicle F is located on a road S1 and will turn left into a road S2. For the left-turn lane of the road S1, a traffic sign (VZ) is applied which is mounted on the left edge of the road and is designed as a stop sign, which makes it mandatory for the driver of the vehicle F to stop at the stop line HL of the left lane before the steering process. Because of the vegetation B disposed at the road edge of the road S2, it is difficult for the driver of the vehicle F to see the road S2 from the stop line HL, the driver usually first slowly groves into the intersection area after resuming travel so that the lateral traffic (e.g., the vehicle F1) on the road S2 can be seen well.

In order to be able to cope well with such traffic conditions with automatic longitudinal guidance, fig. 2 shows a structure of a driver assistance system FAS for a motor vehicle for automatic driving with automatic longitudinal guidance, wherein the longitudinal guidance is started while taking into account a predefinable target speed when the automatic longitudinal guidance is active in an automatic mode. On the specific premise as will be described later in detail with reference to fig. 3, the automatic mode will be switched to the manual mode.

The driver assistance system FAS comprises an evaluation and control unit SE which, when automatic longitudinal guidance is active in the automatic mode, enables speed control in the free-running mode or the following-running mode on the basis of the information present (for example, the environmental information U of the environmental sensor system U, the information about the current speed v and the route guidance navi) taking into account a predefinable target speed. This so-called "active cruise control" maintains a preset desired or target speed (=free running mode) when its own lane is idle. The distance sensor system mounted on the motor vehicle can in particular operate on the basis of radar and/or cameras and/or lasers, if it recognizes a target object or (motor) vehicle travelling ahead on its own lane, adapting its own speed to the speed of the preceding motor vehicle, for example by triggering an appropriate braking torque or driving torque, so that the distance control contained in the "active cruise control" or the corresponding longitudinal control system automatically maintains a target distance suitable for this situation, or more precisely maintains a preset time interval (=following driving mode) with the preceding motor vehicle or target object. If a brake pedal operation is detected in the automatic mode, at least the automatic longitudinal guiding will be interrupted.

The driver assistance system FAS further includes an identification unit in which the first identification unit E1, the second identification unit E2, and the third identification unit E3 are integrated. Also at least the first recognition unit E1, which receives and evaluates the data U of the existing environmental sensor system U, is configured to recognize a defined standstill situation occurring as a result of a preceding automatic braking to standstill process of the motor vehicle. The second recognition unit E2 is configured to recognize the accelerator pedal operation gp. The third identifying unit E3 is configured to identify the brake pedal operation bp.

The situation or operation identified by the three identification units E1, E2 and E3 is transmitted to an evaluation and control unit SE, which is configured to activate the manual mode by issuing a signal aMM when an accelerator pedal operation gp is identified in or during the identified defined stationary situation. With the manual mode activated, the (initially active) automatic mode is deactivated at the same time. If a brake pedal operation bp is detected during manual mode, the automatic longitudinal direction is not interrupted or disabled, contrary to the logic in automatic mode.

In the manual mode, the control unit SE also evaluates information about whether an interruption rule is present. If an interrupt rule is confirmed, the control unit SE triggers deactivation of the manual mode and reactivation of the automatic mode by issuing a signal aAM.

Fig. 3 shows a detailed exemplary embodiment of the method according to the invention. The flowchart shown in fig. 3 starts at step 100 as long as automatic longitudinal guidance is active and speed control takes place in an automatic mode taking into account a predefinable target speed. The automatic mode includes a free running mode and a following running mode known in the art, so that the speed is automatically adjusted to a preset and/or allowable target speed during free running, and an automatic speed control is performed to maintain a preset target distance from the detected target object during the following running mode.

Based on step 100, the necessary information is evaluated in step 200, which information enables the identification of a defined standstill situation that arises as a result of a preceding automatic braking to standstill process of the motor vehicle. In detail, for example, it is monitored whether the vehicle is automatically braked to a standstill due to a traffic sign (for example, a stop sign) temporarily prohibiting the motor vehicle from continuing to travel or due to a traffic sign (for example, a right-side priority rule) requiring the other road user to be given an antecedent. If such a defined rest condition is identified, the accelerator pedal is monitored for operation during the rest phase in step 300. If operation of the accelerator pedal is not detected during the identified standstill condition (i.e., the standstill condition ends due to automatically initiated acceleration or due to allowing or confirming operation of the control element from standstill automatic initiation), the method is aborted and returns to step 100.

However, if an accelerator pedal operation is determined during the defined stationary condition in step 300, then the flow goes to step 400 and a switching from the automatic mode to the manual mode of the automatic longitudinal direction is implemented in the category of step 400. A temporary "manual" speed control is performed during the active manual mode, wherein the travel speed is directly preset by the type of operation with the accelerator pedal. Also, when a brake pedal operation is recognized in the manual mode, the automatic longitudinal guide is not interrupted or deactivated, but only decelerated according to the brake pedal operation.

In step 400, monitoring of the defined interrupt rules continues during the active manual mode. In the sense of an interruption rule, it is for example monitored whether the reached travel speed exceeds a preset speed limit value (for example 10km/h or 20 km/h) and/or whether a specified traffic area (for example an intersection area) has been left and/or whether an existing resume button has been operated to resume the automatic mode. If it is determined that the interrupt rule is satisfied, then go to step 500 and trigger a switch from manual mode (return) to automatic mode. In this automatic mode, as in conventional speed control systems, an automatic longitudinal guidance takes place taking into account a predefinable target speed, i.e. the vehicle accelerates again automatically to a preset or permitted maximum speed as soon as no target object is detected. If a target object is identified, speed control is performed in such a manner that the preset distance from the identified target object is not exceeded.

Thus, by means of the invention, it is possible to fumbly into intersections that are difficult to see, for example, without stopping the automatic longitudinal guidance. By defining appropriate interrupt rules, an automatic and understandable return is made to the automatic mode with fully automated longitudinal guidance.

Claims

1. A driver assistance system (FAS) for a motor vehicle (F) for automatic driving with automatic longitudinal guidance, wherein the automatic longitudinal guidance is initiated taking into account a presettable target speed when the automatic longitudinal guidance is active in an automatic mode, wherein the automatic longitudinal guidance comprises an automatic mode and a manual mode, the driver assistance system comprising:

a first recognition unit (E1) configured to recognize a defined standstill situation during an automatic mode activation of the automatic longitudinal guidance, which defined standstill situation arises as a result of a process of automatic braking to standstill before the motor vehicle (F),

-a second recognition unit (E2) configured for recognizing an accelerator pedal operation (gp), and

-an evaluation and control unit (SE) configured for: activating the automatic longitudinally directed manual mode when an accelerator pedal operation is identified during the identified defined stationary condition; and automatically disabling the manual mode that has been activated when at least one predetermined interrupt rule is satisfied, and triggering a switch from the manual mode back to the automatic mode.

2. Driver assistance system according to claim 1, characterized in that a defined standstill situation is to be identified when the motor vehicle (F) is automatically braked to standstill due to an identified defined traffic infrastructure event (VZ).

3. Driver assistance system according to claim 1 or 2, characterized in that a defined standstill situation is identified when the motor vehicle (F) is automatically braked to standstill due to an identified defined traffic infrastructure event (VZ) requiring that other road users be given antecedent and/or that the motor vehicle is temporarily prohibited from continuing to pass.

4. Driver assistance system according to claim 1 or 2, characterized in that when an accelerator pedal operation (gp) is identified in the defined stationary situation, the manual mode is activated only if no vehicle in front is identified.

5. Driver assistance system according to claim 1 or 2, characterized in that a driving speed dependent on the accelerator pedal operation (gp) is enabled in an activated manual mode.

6. Driver assistance system according to claim 1 or 2, characterized in that the system comprises a third recognition unit (E3), the third recognition unit (E3) being configured for recognizing a brake pedal operation (bp), and the control unit being configured for triggering the braking of the motor vehicle (F) without interrupting or disabling the automatic longitudinal guidance when a brake pedal operation (bp) is recognized in an activated manual mode.

7. Driver assistance system according to claim 1 or 2, characterized in that the activated manual mode is automatically deactivated when the following conditions are fulfilled in the sense of an interruption rule:

-the driving speed exceeds a preset speed limit, and/or

-the distance travelled in the manual mode and/or the distance travelled since the identified traffic infrastructure event (VZ) has exceeded a preset distance limit value, and/or

Identifying an operation on the defined control element,

-leaving a predetermined traffic zone travelled through in said manual mode.

8. Driver assistance system according to claim 1 or 2, characterized in that a driving speed dependent on the accelerator pedal operation (gp) is enabled in the activated manual mode such that the driving speed is at most a speed preset by the accelerator pedal operation (gp).

9. A method for automatic driving of a motor vehicle with automatic longitudinal guidance, wherein the automatic longitudinal guidance is initiated taking into account a predefinable target speed when the automatic longitudinal guidance is active in an automatic mode, wherein the automatic longitudinal guidance comprises an automatic mode and a manual mode, the method comprising the steps of:

identifying a defined standstill condition (200) during an automatic mode activation of the automatic longitudinal guidance, which occurs as a result of a process of automatically braking to standstill before the motor vehicle,

identifying an accelerator pedal operation (300),

-activating the automatic longitudinal guided manual mode (400) when an accelerator pedal operation is identified during an identified defined stationary situation, and

-automatically disabling the manual mode that has been activated when at least one predetermined interrupt rule is satisfied, and triggering a switch back from the manual mode to the automatic mode (500).